The freshwater mussel genus Toxolasma is distinctive for its small adult size — generally less than an inch. At that size, the shells are fully sexually dimorphic in the typical lampsiline style. Good, interesting stuff.

And, speaking of the freshwater mussels of the North America, it seems that we have a new book chapter. Our previous bivalve chapter from Thorp & Covich's invertebrate zoology book (Cummings & Graf, 2009) has been recycled into Thorp & Covich's general freshwater invertebrates book (Cummings & Graf, 2014). We were surprised, too.